Apparatus for spraying liquid on moving articles



D. BARNES June 23, 1970 APPARATUS FOR SPRAYING LIQUID ON MOVING ARTICLESFiled March 18, 196i 2 Sheets-Sheet 1 mvzmon DEREK BARNES June 23, 19700. BARNES 3,516,388

APPARATUS FOR SPRAYING LIQUID ON MOVING ARTICLES Filed March 18, 1968 2Sheets-Sheet 2 INVENTOR DEREK BARNES 1 12% ATTORNEYS United StatesPatent 3,516,388 APPARATUS FOR SPRAYIN G LIQUID ON MOVING ARTICLES DerekBarnes, Vancouver, British Columbia, Canada,

assignor to MacMillan Bloedel Limited, Vancouver, British Columbia,Canada, a corporation of Canada Continuation-impart of application Ser.No. 460,214,

June 1, 1965. This application Mar. 18, 1968, Ser.

Int. Cl. Bc 11/16 US. Cl. 118316 21 Claims ABSTRACT OF THE DISCLOSUREApparatus for spraying liquid, and particularly glue, on one or twosurfaces of articles, such as plywood core veneers, moving through theapparatus including spray guns on one or both sides of a path alongwhich the articles are moved, shield means for protecting the guns fromatomized liquid and to confine liquid overspray rebounding from thearticles, and means for retaining the articles in proper positionrelative to the spray guns without interfering with the application ofthe liquid to said articles.

CROSS-REFERENCES TO RELATED APPLICATIONS This is a continuation-in-partof application Ser. No. 460,214 filed June 1, 1965, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to apparatus forspraying glue or other liquids on to moving articles, and particularlyspraying glue on to wood core pieces used in the manufacture of plywoodpanels.

In the manufacture of plywood, glue is usually applied to cross bandingcore pieces and veneers by rollers or by hand. Spraying of the glue isdesirable, but in the past it has not been very practical because of thedifiiculty involved with getting glue all over the spray guns, the gluelost as a result of overspraying, and getting rid of the excess airwhich is used in the atomizing of the glue.

SUMMARY OF THE INVENTION Although this apparatus is particularlydesigned for spraying glue on to core pieces and panels, it can be usedfor spraying other liquids, such as paint or other coating materials.For the sake of convenience, the invention will be described herein inconnection with glue.

The present apparatus is primarily designed to spray glue on to upperand lower surfaces of wood pieces and the like moved therethrough. Theapparatus protects the spray guns from the glue, confines the oversprayand gathers the overspray glue so that it can be used again, and whennecessary, traps and removes the excess air, which would be dangerous ifbreathed in by a person and would be very objectionable if allowed tocirculate through a plant owing to the fact that it carries fine gluewith it. This gathering of the overspray prevents a finan cial loss thatcould make the spraying of the liquid uneconomical.

Spraying apparatus according to the present invention includes at leastone set of spray guns, and in this example there are upper and lowersets of spray guns, having nozzles projecting towards a path along whichthe articles to be sprayed are moved. Shielding means is provided ateach set of guns to enclose all of said guns, excepting the nozzles orportions of the nozzles thereof. The articles can be moved along thepath in any desired manner, but it is preferable to provide for thispurpose laterally-spaced multiple sets of upper and lower thin "icewires extending along the path to maintain the articles in positionrelative to the gun nozzles as said articles or veneers are movedbetween the wires along the path. The wires can be driven to effectmovement of the articles therebetween, or other means may be provided tomove the articles between the wires, in which case the latter act asguides and keep the articles fiat at this time.

It is preferable to provide outer shielding for each set of guns andenclosing the first-mentioned or inner shielding thereof, said outershielding opening towards the path along which articles are moved sothat glue overspray is confined within the outer shielding. This outershielding is also provided with trough means into which the glueconfined therein drains, said trough means conducting this glue awayfrom the spray guns. Upper and lower exhaust hoods preferably areprovided at the upper and lower outer shielding where the veneer entersand emerges from the latter, said exhaust hoods also opening towards thepath. Exhaust means is connected to these hoods in order to withdraw anyexcess air and fine glue dust which is trapped thereby. An assembly ofspray jets preferably is provided in each exhaust hood, said jets beingpositioned so as to provide an air curtain that acts to divert anyatomizing air and line glue dust therein which pass out of the outershielding into the exhaust hoods in order to prevent said air and dustfrom leaving the apparatus with the veneer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic perspectiveview of the glue spraying apparatus with near Walls thereof broken away,to show parts of its interior,

FIG. 2 is an enlarged vertical cross section taken substantially on theline 22 of FIG. 1,

FIG. 3 is a vertical section taken on the line 33 of FIG. 1, and

FIG. 4 is a section taken on the line 44 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, 10is the glue spraying apparatus which includes an upper set of spray guns12, each having a nozzle 13 projecting downwardly therefrom, said guns12 being mounted on a carriage 14 suspended from rollers 15 that ride onan upper track 16. A set of lower spray guns 18, each having a nozzle 19project upwardly therefrom, is located below upper guns 12. Lower guns18 are mounted on a carriage 20 which is supported by rollers 21 ridingon a lower track 22. N02- zles 13 and 19 extend towards each other, butare spaced apart, so that articles to be sprayed can be moved along apath 25 therebetween. In this example cross banding core pieces 26 aremoved along path 25 by any suitable conveying means, and this conveyingmeans is preferably in the form of multiple sets of upper and lower thinconveyor wires 27 and 28 so arranged that the core pieces are grippedfirmly therebetween. Wires 27 are endless and extend around sets oflower and upper pulleys 259 and 30, each set being mounted on a commonshaft, and said lower pulleys 29, being spring-loaded downwardly in anydesired manner, such as by springs 31 diagrammatically illustrated inFIGS. 1 and 2. Similarly, endless wires 28 extend around upper and lowersets of pulleys 32 and 33 mounted on common shafts. The wire conveyorsare driven in any suitable manner, and a drive belt 3 1 is shown inFIGS. 1 and 2 for driving one set of pulleys 33, said belt beingconnected to a source of power, not shown. A belt 35 connects one of thesets of pulleys 32 to to an adjacent set of pulleys 29. With thisarrangement, all of the wires of the upper and lower conveyors aredriven at the same speed.

If desired, the portions of wires 27 and 28 extending along path 25 maybe stationary, and other means may be provided for moving the corepieces 26 between said wires and along the path. For example, pairs ofupper and lower driven pressure rolls 36 and 37, shown in dotted linesin FIG. 2, may be provided at the beginning and end of path 25, forrespectively pushing and pulling the core pieces along the path. Therolls are grooved to receive wires 27 and 28 so that the rolls pressagainst core pieces located between the wires, and the wires act asguides for the core pieces and keep them flat as they travel along thepath.

Spray guns 12 and 18 are preferably the internal airmix type, and guns12 have a glue header 38, an atomizing air header 39 and a control airheader 40 connected thereto by suitable tubes, see FIG. 2. The operationof this type of gun is known and does not require description herein.Spray guns 18 have a glue header 41, an atomizing air header 42 and acontrol air header 43 connected thereto by suitable piping.

Inner shielding is provided around spray guns 12 to protect them fromthe glue discharged through their nozzles 13. The inner shielding is ashield 45 which is roughly V-shaped in cross section. The nozzles 13 ofthe guns project downwardly from a lower wall 47 of the shield, and saidshield has side walls 48 and 49 which extend upwardly and outwardly fromwall 47 to an upper cross wall 50 which is mounted on carriage 14. Theends of the shield 45 are closed by end walls 51, see FIG. 3. Thus,shield 45 completely encloses guns 12 while nozzles 13 of the gunsprojecting downwardly from said shield.

An outer shield 53 is provided for guns 12 and inner shield 45. Thisouter shield 53 is preferably in the form of an inverted U in crosssection and has side walls 55 and 56 extending upwardly from lower edges57 and 58, respectively, located near path 25. A cross wall 59 joins theupper parts of walls 55 and 56 and extends over track 16 and shield 45.Doors 61 close the opposite ends of shield 53, tracks 16 and 22extending through holes in one of said doors. Shield 53 confinesoverspray from the gun nozzles. Overspray is glue spray which bouncesoff the core pieces and/or travels somewhat laterally from nozzles 13.

Troughs 62 and 63 are formed along the lower edges 57 and 58 of shield53 inwardly of said edges. Any glue deposited on the inner surface ofshield 53 runs down said surface into troughs 62 and 63. The glue drainsfrom the troughs at both ends thereof either into a trough extending outfrom the apparatus, or into a bottom drain section. Any glue thatdeposits on the outer surface of walls 48 and 49 of inner shield 45 willflow down these walls and into the glue spray emerging from nozzles 13.

The lower set of spray guns 18 is provided with an inner shield 70 whichis roughly in the form of an inverted V in cross section. Shield 70 hasan upper wall 72 through which nozzles 19 project, and side walls 74 and75 which extend downwardly and away from each other to a lower crosswall 76 which is mounted on carriage 20. The ends of shield 70 areclosed by end walls 77. This shield encloses guns 18 while the nozzles19 thereof project upwardly therefrom.

A lower outer shield 79 encloses track 22 and shield 70 of lower guns18. Shield 79 is preferably in the form of a U in cross section and hasside walls 81 and 82 extending downwardly from outwardly flaring upperedges 84 and 85 near path 25 to a cross wall or bottom 86 extendingtherebetween below shield 70. The ends of shield 79 are closed by doors61. Wall 86 is substantially V- shaped in cross section to form acentral trough 89 extending from one end to the other of shield 79. Apipe 91 is connected to trough 89 and extends out of the apparatuspreferably to a pump and a 3-way valve that directs the overspray glueto the reservoir which supplies glue to the spray gun, or wash-water toa drain. In

this example, troughs 62 and 63 of upper shield 53 drain into trough 89.

Inner shield 70 projects lower guns 18 from the glue, and any glue whichaccumulates on the outer surfaces of walls 74 and 75 will flow down saidwalls and drop on to cross wall 86 of outer shield 79, whence it flowsinto trough 89 and out of the apparatus. Similarly, any glue whichaccumulates on the inner surfaces of side walls 81 and 82 or outershield 79 flows down said inner surfaces to cross wall 86 and trough 89.

A pair of closed upper exhaust hoods 95 and 96 are mounted on the outersurfaces of upper shield walls 55 and 56 and open towards path 25 at 98and 99. Stacks 102 and 103 extend from the top of hoods 95 and 96 eitherto atmosphere outside the building in which the apparatus is located, orto suitable separating apparatus, not shown, for reclaiming the fineglue from the atomizing air. A pair of closed lower exhaust hoods 106and 107 are mounted on the outer surfaces of lower shield walls 81 and82 and open towards path 25 at 109 and 110, respectively. Drain pipes112 and 113 extend from the bottoms of hoods 106 and 107 and extend to adrain, not shown. It will be noted that outer shields 53 and 79, andhoods 95, 96, 106 and 107 extend laterally beyond the ends of innershields 45 and 70 and the edges of core pieces 26, see FIGS. 1 and 3, sothat there is intercommunication therein between the upper and lowerouter shields and the upper and lower hoods. As a result, stacks 102 and103 function for lower hoods 106 and 107 as well as for the upper hoods.Core pieces 26 are moved along path 25 between the adjacent edges ofupper and lower shields 53 and 79, hoods 95 and 106, and hoods 96 and107.

Upper air jets 116 and 117 are provided in hoods 95 and 96, and lowerair jets 119 and 120 are provided in lower hoods 106, and 107. The jetsin each pair of upper and lower hoods are located along the open edgesof said hoods and are directed towards a point between the edges ofthese hoods and the adjacent shields 53 and 79, providing an angled aircurtain that directs the outward rushing streams of atomizing air andglue dust, upwardly and downwardly into hoods 95-106 and 96-107. Thesehoods withdraw this excess air which is discharged from gun nozzles 13and 19 as a result of atomizing the glue. Exhaust pipes 102 and 103withdraw the entrapped air from all of the hoods.

The operation of spraying apparatus 10 is apparent from the abovedescription. As core pieces 26 are moved along path 25 through apparatus10, upper and lower guns 12 and 18 spray glue onto the upper and lowersurfaces of said pieces through their respective nozzles 13 and 19. Guns12 and 18 are aligned so that the spray therefrom covers the entireupper and lower surfaces of the core pieces.

The steel wires 27 and 28 are very narrow, preferably inch in diameter,and are preferably extended through the intersection of two spraypatterns from guns 12 and 18. The wires do not materially affect theapplication of glue to the surfaces of the core pieces. These wires arecleaned of glue with any suitable wiping mechanism, not shown. Innershields 45 and 70 protect the upper and lower guns and their associatedparts from the glue and either direct any glue accumulating thereon backto the glue spray emerging from the nozzles or to the troughs leadingout of the apparatus. Outer shields 53 and 79 confine the overspray, andglue accumulating on the inner surfaces of these shields is directed outof the apparatus by troughs 62, 63 and 89. Upper and lower hoods 95-96and 106-107 trap the excess air from the spray nozzles, and this isexhausted out of the apparatus through pipes 102 and 103.

If desired, only one set of spray nozzles may be used for sprayingeither the upper or the lower surfaces of articles being moved pastthem. For example only upper guns 12 may be used, in which case lowerguns 18 and lower shield 70 would not be required. If this were apermanent condition, lower shield 79 could be much shallower than shown.Conversely, guns 12 and upper shield 45 can be omitted, and guns 18 onlyused.

I claim:

1. Apparatus for spraying liquid onto moving articles directedtherethrough, comprising a set of spray guns having nozzles projectingtowards a path along which articles are moved, laterally-spaced multiplesets of upper and lower thin wires extending along said path andarranged to firmly grip the articles therebetween to maintain the latterflat and to support said articles in a horizontal plane and in positionrelative to the gun nozzles as said articles are moved between the wiresalong the path, said set of guns being adapted to be connected to aliquid source and to atomize liquid therefrom and to spray said'atomizedliquid through their respective nozzles onto surfaces of the movingarticles, and shield means for the guns to shield said guns from theatomized liquid.

2. Apparatus as claimed in claim 1 in which each of said wires isendless, and including means for moving said wires along the path tomove articles gripped thereby along said path.

3. Apparatus as claimed in claim 1 including a second set of spray gunshaving projecting nozzles and positioned on the side of said path andsaid wires opposite said first-mentioned guns, said second set of gunsbeing adapted to be connected to liquid source means and to atomizeliquid therefrom and to spray said atomized liquid through theirrespective nozzles onto the opposite surfaces of the moving articles,and shield means for the second set of guns to shield the latter fromthe atomized liquid.

4. Apparatus as claimed in claim 3 in which each of said wires isendless, and including means for moving said wires along the path tomove articles gripped thereby along said path.

5. Apparatus for spraying liquid onto moving articles directedtherethrough, comprising a set of spray guns having nozzles projectingtowards a path along which articles are moved, laterally-spaced multiplesets of upper and lower thin wires extending along said path andarranged to firmly grip the articles therebetween to maintain the latterflat and to support said articles in a horizontal plane and in positionrelative to the gun nozzles as said articles are moved between the wiresalong the path, said set of guns being adapted to be connected to aliquid source and to atomize liquid therefrom and to spray said atomizedliquid through their respective nozzles onto surfaces of the movingarticles, inner shield means for said gun set extending from the nozzlesthereof in the direction away from said path to shield the guns fromatomized liquid, outer shield means for the set of guns extendingsubstantially from said path away therefrom and around said gun set andthe inner shield means thereof to confine liquid overspray reboundingfrom the articles, and opposed shield means on the opposite side of saidpath from said outer shield means and opening towards the path to catchany atomized liquid moving past the articles travelling along the path.

6. Apparatus as claimed in claim 5 including a closed hood outside saidouter shield means and opening towards the path to trap any excess airintroduced during the atomization of the liquid, and exhaust meansconnected to said hood for removing the entrapped air.

7. Apparatus as claimed in claim 6 including air jets in the hoodarranged to provide air curtains in said hood to divert into the hoodatomized liquid which passes out of said outer shield means.

8. Apparatus for spraying liquid on to moving articles directedtherethrough, comprising sets of upper and lower spray guns havingprojecting nozzles and positioned above and below a path along whicharticles are moved, laterally-spaced multiple sets of upper and lowerthin wires extending along said path and arranged to firmly grip thearticles therebetween to maintain the latter flat and to support saidarticles in a horizontal plane and in position relative to the gunnozzles as said articles are moved between the wires along the path,said sets of guns being adapted to be connected to a liquid source meansand to atomize liquid therefrom and to spray said atomized liquidthrough their respective nozzles on to opposite surfaces of the movingarticles, inner shield means for each of said gun sets extending fromthe nozzles thereof in the direction away from said path to shield theguns from atomized liquid, and outer shield means for each of the upperand lower gun sets extending substantially from said path away therefromand around said each gun set and the inner shield means thereof toconfine liquid overspray rebounding from the articles.

9. Apparatus as claimed in claim 8 including closed upper and lowerhoods outside the upper and lower outer shield means above and belowsaid path and opening towards the latter to trap excess air introducedduring the atomization of the liquid, and exhaust means connected tosaid hoods for removing the entrapped air.

10. Apparatus as claimed in claim 9 including air jets in the upper andlower hoods arranged to provide air curtains in said hoods to divertinto said hoods liquid which passes out of said outer shield means.

lll. Apparatus for spraying liquid on to opposite surfaces of articlesdirected therethrough, comprising sets of upper and lower spray gunshaving projecting nozzles and positioned above and below a path alongwhich articles are moved, laterally-spaced multiple sets of upper andlower thin wires extending along said path and arranged to firmly gripthe articles therebetween to maintain the latter flat and to supportsaid articles in a horizontal plane and in position relative to the gunnozzles as said articles are moved between the wires along the path,said sets of guns being adapted to be connected to a liquid source meansand to atomize liquid therefrom and to spray said atomized liquidthrough their respective nozzles on to opposite surfaces of the movingarticles, an inner shield enclosing each of the gun sets and from whichthe nozzles of the guns of said sets project, said inner shieldsprotecting the guns from atomized liquid, and an outer shield enclosingeach of the upper and lower gun sets and the inner shields thereof, saidouter shields being open to said path and confining liquid oversprayrebounding from the articles.

12. Apparatus as claimed in claim llll including closed upper and lowerhoods outside the upper and lower outer shields above and below saidpath and opening towards the latter to trap excess air introduced duringthe atomization of the liquid, and exhaust means connected to said hoodsfor removing the entrapped air.

13. Apparatus as claimed in claim 12 including air jets in the upper andlower hoods arranged to provide air curtains in said hoods to divertinto said hoods atomized liquid which passes out of said outer shields.

14. Apparatus as claimed in claim Ill in which the upper outer shield isin the form substantially of an inverted U in cross section and havingside walls extending upwardly from lower edges near said path and across wall extending between said side walls, and including troughsformed along said lower edges of the side walls inwardly thereof.

15. Apparatus as claimed in claim lll in which the lower outer shield isin the form substantially of a U in cross section and having side wallsextending downwardly from upper edges near said path and a cross wallextending between said side walls, and including a trough formed in saidcross wall beneath the lower set of guns and the inner shield thereof.

16. Apparatus as claimed in claim 15 in which the inner shield of thelower set of guns is in the form of substantially an inverted V in crosssection having side walls extending downwardly and outwardly towards thecross wall of the lower outer shield, whereby liquid can drain off saidside walls on to said cross wall.

17. Apparatus as claimed in claim 11 in which the inner shield of theupper set of guns is substantially in the form of a V in cross sectionhaving side walls extending downwardly and inwardly towards the nozzlesof said upper gun set, whereby liquid can drain off said side walls intothe atomized liquid being discharged by the noules.

18. Apparatus for spraying liquid on to moving articles directedtherethrough, comprising a set of spray guns extending laterally acrossa path along which flat horizontally arranged articles are moved andhaving nozzles projecting towards said path, said set of guns beingadapted to be connected to liquid source means and to atomize liquidtherefrom and to spray said atomized liquid through their respectivenozzles on to surfaces of the moving articles, an inner shield extendingtransversely of the path and enclosing the gun set and from which thenozzles of the guns project, said inner shield protecting the guns fromatomized liquid, an outer shield extending transversely of the path andenclosing the gun set and the inner shield thereof and opening towardssaid path and confining liquid overspray rebounding from the articles,said outer shield having side Walls perpendicular to and terminating atthe path on opposite sides of the inner shield and a wallinterconnecting said side Walls outwardly of the inner shield, anexhaust hood on the outer surface of each of said side walls of theouter shield opening towards the path, each hood having an outer wallspaced from said adjacent side wall perpendicular to the path andterminating at the latter, exhaust stacks connected to the hoods, andair jets in the hoods across the path directed away from the hood sidewalls and towards the path and the adjacent outer shield side walls.

19. Apparatus as claimed in claim 18 including a second set of sprayguns on the opposite side of said path from and similar to thefirst-mentioned set of guns and having nozzles projecting towards thepath, an inner shield extending transversely of the path and enclosingthe second gun set and from which the nozzles thereof project, a secondouter shield extending transversely of the path and enclosing the secondgun set and the inner shield thereof and opening towards the pathsimilar to and opposing the first-mentioned outer shield, drainage meansconnected to said second outer shield, second exhaust hoods on outersurfaces of said second outer shield opening towards the path andsimilar to and opposed to the first-mentioned hoods, drainage meansconnected to said second hoods, and air jets in the second hoods acrossthe path directed towards the path and the adjacent second outer shield.

20. Apparatus as claimed in claim 19 including laterally-spaced multiplesets of upper and lower thin wires extending along said path between theopposed gun sets, outer shields and hoods and arranged to grip saidarticles therebetween to maintain the latter fiat and in positionrelative to the gun nozzles as said articles are moved between the wiresalong the path.

21. Apparatus as claimed in claim 20 in which each of said wires isendless, and including means for moving said wires along the path tomove articles therebetween along said path.

References Cited UNITED STATES PATENTS 1,751,712 3/1930 Owen.

2,217,724 10/ 1940 Birmingham 118-324 X 2,675,646 4/1954 Kramer et al118-316 X 2,960,061 11/1960 Whitbeck 118-314 X 2,848,353 8/1958 Norris118-326 X 3,270,711 9/1966 Leach 118-316 X OTHER REFERENCES 1,033,113,German Auslegeschrift, June 1958, Walther.

JOHN P. McINTOSH, Primary Examiner US. Cl. X.R. 118-324, 326

